High-loading electrodes play a crucial role in the practical applications of high-energy-density batteries, which are especially challenging for lithium–sulfur (Li–S) batteries. Herein, a mechanically robust network binder was constructed by weaving dual biopolymers (i.e., guar gum and xanthan gum) via the intermolecular binding effect of extensive functional groups in both polymers. This network binder was capable of effectively preventing polysulfides within the electrode from shuttling and, consequently, improved electrochemical performance. A remarkably high sulfur loading of 19.8 mg cm⁻² and an ultrahigh areal capacity of 26.4 mA h cm⁻² were achieved as a result of the robust mechanical properties of the network binder. This study paves a new way for obtaining high-energy-density batteries by the simple application of robust network biopolymer binders that are inherently low-cost and environmentally friendly.

Long-term stability and high-rate capability have been the major challenges of sodium-ion batteries. Layered electroactive materials with mechanically robust, chemically stable, electrically and ironically conductive networks can effectively address these issues. Herein we have successfully directed carbon nanofibers to vertically penetrate through graphene sheets, constructing robust carbon nanofiber interpenetrated graphene architecture. Molybdenum disulfide nanoflakes are then grown in situ alongside the entire framework, yielding molybdenum disulfide@carbon nanofiber interpenetrated graphene structure. In such a design, carbon nanofibers prevent the restacking of graphene sheets and provide ample space between graphene sheets, enabling a strong structure that maintains exceptional mechanical integrity and excellent electrical conductivity. The as-prepared sodium ion battery delivers outstanding electrochemical performance and ultrahigh stability, achieving a remarkable specific capacity of 598 mAh g⁻¹, long-term cycling stability up to 1000 cycles, and an excellent rate performance even at a high current density up to 10 A g⁻¹.

Being simple, inexpensive, scalable and environmentally friendly, microporous biomass biochars have been attracting enthusiastic attention for application in lithium-sulfur (Li-S) batteries. Herein, porous bamboo biochar is activated via a KOH/annealing process that creates a microporous structure, boosts surface area and enhances electronic conductivity. The treated sample is used to encapsulate sulfur to prepare a microporous bamboo carbon-sulfur (BC-S) nanocomposite for use as the cathode for Li-S batteries for the first time. The BC-S nanocomposite with 50 wt.% sulfur content delivers a high initial capacity of 1,295 mA·h/g at a low discharge rate of 160 mA/g and high capacity retention of 550 mA·h/g after 150 cycles at a high discharge rate of 800 mA/g with excellent coulombic efficiency (⩾95%). This suggests that the BC-S nanocomposite could be a promising cathode material for Li-S batteries.